A physically unclonable function (PUF) may provide an unpredictable digital value. Each individual PUF provides a different digital value even when the exact manufacturing process is given and the same design and the same process are used.
Thus, a PUF may also be referred to as a physical one-way function practically impossible to be duplicated (POWF).
Such a PUF characteristic may be used for generating an encryption key for security and/or authentication. For example, a PUF may be utilized to provide a unique key to distinguish devices from one another.
KR Patent Registration No. 10-1139630 (hereinafter, “Patent 630”) discloses a PUF embodying method. Patent 630 presents a method for stochastically determining using a process variation whether an inter-layer contact or via is formed between semiconductor conductive layers.